LOS ANGELES, 21 Feb 2015 (AFP) - With the classic Riviera Country Club course showing it's teeth, Goosen survived some shaky moments, two late birdies helping him to a 54-hole total of eight-under par 205 and a two-stroke lead over Canadian Graham DeLaet.
DeLaet, who started the day tied for second one stroke adrift, carded a one-under par 70 for 207.
On a crowded leaderboard, South Korea's Bae Sang-Moon headed a group on 208 after an impressive bogey-free five-under par 66.
He was joined at five-under by Spain's Sergio Garcia, who carded an adventurous 68, 23-year-old Mexican Carlos Ortiz (68) and American J.B. Holmes (69).
Eight players shared seventh on four-under 209, including former world number one Vijay Singh, who will celebrate his 52nd birthday on Sunday.
Other former major winners joining Singh on four-under were reigning Masters champion and defending Northern Trust Open champ Bubba Watson, Argentina's Angel Cabrera and American Jim Furyk.
Americans Jordan Spieth, Dustin Johnson, James Hahn and Ryan Moore were also on 209.
Goosen is more than a decade removed from his second US Open triumph in 2004, and hasn't won a US PGA Tour event since 2009.
The 46-year-old, who had back surgery in 2012, admitted on Friday he wasn't sure how his game would hold up.
But he stretched his lead to three strokes when he rolled in a 35-foot putt at the eighth for his third birdie of the day.
That lead then dwindled on the back nine as his struggles off the tee caught up with him on the firm, unforgiving course.
"The first nine was really putting, a lot of good recovery putts," Goosen said.
"I didn't hit the ball that great on the back nine, especially my driver, and I put myself in a few bad places.
"But I still made some good putts," added Goosen, who said his bogey putts at 13 and 15 were crucial as they meant he "didn't do that much damage to the scorecard as double-bogeys would do."
From the 10th through the 15th, Goosen had four bogeys and one birdie and just one par.
A chip-in for birdie from 35 feet at the par-three 16th was a needed boost, and he picked up another stroke with a birdie at the par-five 17th.
"It wasn't easy out there for me," Goosen said. "Mentally-wise, I had to work hard to try and stay positive and focused. But I'm still in the lead, so that's a good place to be."
DeLaet, seeking his first US PGA Tour victory, opened with an eagle and added three birdies, but four bogeys ensured he never got his nose in front of Goosen.
"I'm happy shooting under par," DeLaet said. "It's a tough golf course. It's just so demanding and tests your patience."
- Garcia's great escape -
Among the group tied for third, Bae is seeking his second win of the current campaign after his victory in the 2014-15 season-opening Frys.com Open in October.
He opened with back-to-back birdies and nabbed another brace of birdies at six and seven. He made just one more birdie, at the 10th.
Garcia's round included an astonishing par at the 13th, where his errant tee shot found a bunker behind the 10th green.
He used a three-iron to blast out between a tree and a television tower, eventually making a 15-foot par-saving putt.
"I would have been happy with five, so four was a bonus," Garcia said.
Leading third-round scores on Saturday in the $6.7 million US PGA Tour Northern Trust Open (USA unless noted, par-71):
205 - Retief Goosen (RSA) 66-70-69
207 - Graham DeLaet (CAN) 70-67-70
208 - Bae Sang-Moon (KOR) 71-71-66, Carlos Ortiz (MEX) 67-73-68, Sergio Garcia (ESP) 71-69-68, J.B. Holmes 70-69-69
209 - Dustin Johnson 70-72-67, Jim Furyk 71-70-68, James Hahn 66-74-69, Vijay Singh (FIJ) 66-74-69, Jordan Spieth 69-70-70, Angel Cabrera (ARG) 70-68-71, Bubba Watson 70-69-70, Ryan Moore 69-68-72
210 - Vaughn Taylor 74-68-68, Morgan Hoffmann 69-75-66, Paul Casey (ENG) 70-69-71
211 - Keegan Bradley 73-68-70
212 - Pat Perez 69-73-70, Hideki Matsuyama (JPN) 70-72-70, Michael Putnam 70-72-70, Ken Duke 72-70-70, Harris English 72-69-71, Brendon Todd 69-72-71